In the related art, a double-barreled handgun has been described, e.g., in U.S. Patent Publication No. 2012/0291324, issued to Bandini, involving a double-barreled handgun that fires both chambers simultaneously. U.S. Pat. No. 1,202,707, issued to Grieco, involves a double-barreled handgun that fires from one of the two barrels at a time and allows the user to selectively choose which barrel from which to fire. The Grieco firearm, however, utilizes a shaft to engage one of two hammers in order to prevent the firing from both barrels. This shaft extends beyond the contour of the firearm and can be easily damaged and rendered inoperable. Further, in order to prevent ammunition from entering the chamber of the non-firing barrel, the Grieco firearm utilizes manually controlled stop plates. Accordingly, the Grieco handgun is prone to damage and inoperability. Therefore, a need exists for a double-barreled handgun that addresses the shortcomings in the related art.